In the case of high-performance objectives such as are used for example as projection objectives in projection exposure apparatuses for microlithography for the production of semiconductor components, in particular in the EUV range, the optical elements used therein, such as, for example, lenses or mirror elements and the like, desirably have a very high positional accuracy (e.g. of an order of magnitude of less than 100 pm in the EUV range). Often, this can be achieved, inter alia, only when no undesired or parasitic mechanical effects are introduced onto the optical elements and/or the optical assemblies in which the optical elements are mounted. Undesired or parasitic mechanical effects are those mechanical effects which are not caused by the mounting of the optical element as such. Parasitic mechanical effects encompass qualitatively mechanical friction and damping, mechanical stresses, mechanical forces and moments, in particular owing to mechanical short circuit with respect to the structure (such as housing, measuring structures or the like), for example via cable connections, and also vibrations or interference excitations in the higher-frequency range (e.g. greater than 20 Hz in the EUV range).
For the correction of image aberrations in projection objectives for semiconductor lithography, it is known to use of two basic types of manipulators, position manipulators and deformation manipulators. In the case of the position manipulators, the sensitivity of the optical effect of an optical element to the change in position thereof is utilized to achieve the desired correction of the wavefront in the case of a suitable displacement. In contrast thereto, in the case of deformation manipulators, the sensitivity of the optical effect of an optical element to mechanical deformation is utilized to obtain the desired correction effect.
A deformation manipulation of an optical element in a projection objective of a projection exposure apparatus for microlithography is known from US 2007/0036494 A1.
In order to be able to carry out such mechanical actuations or manipulations, the optical element or the optical assembly is provided with corresponding sensors, actuators and, if appropriate, a control device. These devices have to be supplied with energy and also actuating and measurement signals. This can be associated with the problem of carrying out these energy and control or regulating signal transmissions without introducing undesired or parasitic forces and moments and also vibrations onto the internally mounted optical or mechanical element. This cannot be ensured in the case of known cable connections.
Reference is made to US 2005/0140955 A1 and DE 10 2005 062 081 A1.